Method of making a chair



Feb- 8, 1966 E. wooDARD ETAL 3,234,314

v INVENTORS $222012 E Woodard F352 7 Edzqz'zz oedezlzn BY M7 A4/VM- Feb 8, 1966 L. E. WOODARD ETAL 3,234,314

METHOD OF MAKING A CHAIR Filed June 4, 1964 3 Sheets-Sheet 2 I N VENTORS kg/222022 E fdfoodawd Edzgzz DaedezjZLL/rz M u? ATTORNEYS BY M w/ YW Feb. 8, 1966 1 E. wooDARD ETAL 3,234,314

METHOD OF MAKING A CHAIR Filed June 4, 1964 5 Sheecs-Sheet 5 2g j 6 INVENTURS lignee-Z22 E Woodard Edy/faire Doedezjla'fz BY i@ @w1/@7% Jr/@- ATTORNEYS United States Patent C) 3,234,314 METHD GF MAKNG A CHAIR Lyman E. Woodard and Edwin A, Boederlein, (wosso, Mich., assigner to Woodard lvanntacturing Company, Owosso, llvlich.7 a corporation of Michigan Filed Sinne 4, i954, Ser. No. 372,646 d Claims. SCI. 26d-271) This invention generally relates to a chair and the method of making the Same and more particularly relates to a chair having a thermoplastic seat wrapped on the frame thereof and a method of attaching a thermoplastic seat to a chair frame.

Hard thermoplastic seats have been attached to chair frames by external clamping or gripping devices as well as by being snapped thereon by the seats integral extruded or molded flexible sprinor snapping lower portion. However, snapped-on chair seats rit relatively loosely on the chair frame and allow limited relative movement therebetween, or else, they are so tight that diiculties are experienced in attaching them onto chair seat frames. Also, tight tensioned or biased engagement of thermoplastic seats place undue stress on the plastic which results in premature rupture thereof. Premature rupturing also occurs with the use of external clamping means that not only increase the cost of the chairs but also provides a plurality of possible rupture points.

It is therefore an object ofthe present invention to provide a `hard substantially untensioned or unbiased thermoplastic chair seat wrapped around a seat frame and an object to provide a method of wrapping a hard thermoplastic chair seat around a chair trarne.

It is another object of the present invention to lirst make pliable preselected portions of a hard thermoplastic chair seat, then wrapping said pliable chair seat portions around a seat frame and then hardening said wrap-around portions to secure said seat to the seat frame.

It is another object of the present invention to provide an improved wrap-around thermoplastic chair seat.

it is still another obyect of the present invention to provide a hard thermoplastic chair seat having four separate integral downwardly extending ange or lip portions.

lt is still another object of the present invention to provide a method of wrapping a hard thermoplastic chair seat around a metal chair frame wherein the wrap-around portions of the chair seat are lirst heated by radiation to maire the thermoplastic material pliable, and simultaneously wrapping all the pliable wrap-around portions of the thermoplastic seat around the chair frame to secure the chair seat to the chair frame.

Other objects, features and advantages of the present invention will become apparent to those skilled in the art after a careful consideration of the following detailed description when tal-:en in conjunction with the drawings wherein like reference numerals refer to like and corresponding parts.

In the drawings:

FIGURE l is a perspective View of a chair seat constructed in accordance with the principles of the present invention;

FIGURE 2 is a partial transverse cross-sectional View with parts in elevation of a chair seat on a chair frame being in position for one of the steps of attaching the chair seat to the chair frame in accordance with the principles of the present invention;

FIGURE 3 is a partial longitudinal cross-sectional View with parts in elevation illustrating the position for another step of wrappinfy the chair seat to the chair frame in accordance with the principles of the present invention;

FIGURE 4 is a partial longitudinal cross-sectional view with parts in elevation illustrating another of the steps in 3,234,3l4 Patented Feh. 8, i966 ICC the method of making a chair in accordance with the principles of the present invention;

FIGURE 5 is a partial longitudinal cross-sectional view with parts in elevation illustrating still another step in wrapping a chair seat around a chair frame in accordance with the principles of the present invention;

FGURE 6 is a partial longitudinal cross-sectional view with parts in elevation illustrating a further step in wrapping the chair seat around a chair frame in accordance with the principles of the present invention; and

FIGURE 7 is a perspective View of a chair constructed in accordance with the principles of the present invention.

As shown in the drawings:

A molded four sided hard thermoplastic chair seat having a concave or converging outer face and having four separate downturned flanges extending integrally from the sides of the seat. One flange extends from each side of the chair seat with the sides of adjacent ilanges being separated at the corners of the seat and two opposite side flanges each having one arm groove formed therein.

The hard thermoplastic chair seat is placed on a chair frame and the chair frame and seat are located on a. wrapping table with the seat outer face facing the table top and the seat flanges extending upwardly away from the table top. The iianges are first heated by radiation until they are pliable. After the flanges are heated Sulliciently, the heating is stopped and four wrap-around bars are simultaneously raised and placed in engagement with the pliable upwardly extending flanges. The wraparound bars iirst bend the flanges radially inwardly and then downwardly around the chair seat frame bars towards the seat undersurface to have tight iitting engagement therewith and with the ends of the flanges in contact with the seat undersurface. After the anges are wrapped around the chair seat frame bars, the pliable anges are allowed to cool and harden in their wraparound position and the Wrap-around bars are removed. Thus, the chair seat is now permanently wrapped around the chair frame in an unbiased condition.

Referring to FIGURES l and 2 there is illustrated a molded four sided hard thermoplastic seat 10 having a concave or converging seat face 11 converging from the four sides l2, 13, 14 and 16.

Downwardly extending from the sides 12 and i3 are respective integral front and rear flanges or lips i7 and 17a and from the respective sides i4 and 16 are integral side lianges or lips 18 and 18a.l The four flanges are separated from one another at the four corners i9 of the chair seat 1?. The iianges 17, 17a, 18 and l8r; have chamtered or converging sides 21, 21a, 22 and 22a respectively. The two opposite side lianges 18 and 18a, have grooves 23 and 23a formed therein (FIGURE 2) in order to allow the llanges i3, l8r! to be wrapped around chair seat ltrarne bars 27 and 28 which also have arm rest legs 3l attached thereto.

The chair seat itl is molded from any suitable thermoplastic material into the hard relatively rigid form illustrated by FIGURE l. The thermoplastic material may be Kralastic which is a styrene copolymer alloyed with a rubber copolymer, or any other suitable thermoplastic material.

Referring to FIGURE 2, the plastic seat 1@ is placed on a chair having a chair seat trarne with interconnected frame rods or bars 24, 26, 27 and 2S which have the same outer peripheral contour as the inner periphery of the chair seat :and the bars are adapted to extend within the confines of the ilanges i7, 17a, l and ida and have their outer peripheral surfaces engaging the inner surfaces of the ilanges 17, l'a, 18 and 18a as well as having the upper surface of the seat frame bars engaging the undersurface of the seat. The lianges are of a suiicient width such that their end walls Ztl extend a predetermined distance beyond the seat frame 'ears and there are corner separations between the sides of the flanges which are predetermined such that the flanges will not be hindered by chair legs 29 when the flanges are wrapped iaround the respective seat frame bars 24, 26, 27 and 28. Also, the slots 23 and 23a in the side flanges 27 and 28 are of a predetermined size in order to allow the anges to be folded or Wrapped without any interference from the `arrn rest legs 31 which are connected to the chair side frame bars 27 and 28.

Referring to FIGURES 2 through 6, there is shown a suitable wrapping table 32 having a top platform 33 for supporting the seat face 11 and a bottom platform 35 for supporting the table. A heating means 34, not shown in FIGURES 3-6 for the sake of simplicity, is pivotally connected to the table by appropriate pivot means 36. The heating means has two rectangular trough-like angular casings 37 and 3S which have the open mouth thereof facing the outer surfaces of the anges 17, 17a, 18 and 18a. The angular casing 37 has la forward portion 39 with its mouth being shaped contiguous with the rear flange 17a and a rear portion 41 with its mouth being shaped contiguous with the side flange 18a. Likewise, the angular casing 38 has a forward portion 42 whose mouth is contiguous with the side flange 18 and a rear portion 43 Whose mouth is contiguous with the front flange 17. The casings 37 and 38- contain therein angular white heating elements 44 and 46 respectively that extend substantially the length thereof and which are spaced from the open mouth of the casings. The heating elements 44 and 46 are similar to those utilized for an electric stove. It is of course understood that any other suitable heating means may be utilized if desired.

The heating casings are pivotally connected `at one of their joining ends by pivot pin 36 such that the casings may be pivoted to the heating position which is with their 'open mouths in close proximity to the outer surfaces of the flanges, as illustrated in FIGURE 2, and pivoted out of heating position away from the flanges, as is illustrated by the dotted lines in FIGURE 2.

When the heating casings 37 and 3S are in their closed position with the casings circling the outer surfaces of the flanges, asshown in FIGURE 2, the heating coils radiantly heat at a predetermined temperature and for a predetermined time, the thermoplastic seat anges along their 'entire length for a predetermined portion of their width, until the hard thermoplastic material thereof is sufficiently pliable such that it may be shaped as desired. The time and temperature are dependent upon the properties of the thermoplastic material. After sutticiently heating flanges, the casings 37 and 38 are pivoted away from the seat flanges as indicated by the dotted lines in FIGURE 2 and which are in condition to be Wrapped taround the seat frame bars24, 26, 27 and 28.

Referring to FIGURES 2 through 6, the wrapping table 32 has a central guide or leg cylinder S4 and two diametrically opposed guide cylinders or legs 57, 57 which interconnect the table top platform 33 and the table base platform 35. A cylindrical vertical control sleeve 53 is slid- 'ably mounted on the guide cylinder 54 and has its base acting as a hub for four equally spaced radial arms 52. Suitable lifting means (not shown) are connected to the control sleeve for moving it axially along the guide cylinder 54.

Two cylindrical horizontal control sleeves 58 `are slidably mounted on the guide legs 57, S7. Each horizontal control sleeve has mounted thereon two guide arms 59 and 6) which are spaced a predetermined distance apart and are spaced radially outwardly from the sleeve 58 and which extend axially from one end thereof. The guide arms 59 and 60 each have formed therein an angular guide slot 61. The angular guide slots 61 are formed such that they each have two vertically extending end portions 62 and 63 which extend substantially perpendicular to the table top and with radially spaced longitudinal center lines. The slot portions 62 and 63 extend for a predetermined distance and are interconnected by a slanted or angular slot portion 64 extending inwardly from the slot portion 62 to the slot portion 63. The sleeve 58 have suitable lift means (not shown) attached thereto to raise and lower the horizontal control sleeves 5S on the guide legs 57, 57.

Four angular pivot arms 66 each have one end pivotally connected to one end of a corresponding radial arm 52 by a suitable pivot pin 63. Suitably connected to the other ends of the pivot arms 66 by means 67 are arm clamps 47, 48, 49 and 51.

f Extending interme-diately from each pivot [arm 66, adjacent the angle portion thereof, is a bifurcated guide member 69 that extends towards one of the guide arms 59 or 60. The bifurcated guide members preferably overlap the guide arms such that guide rolls 71, connect to the ends of each bifurcated guide members, slide in the appropriate guide arm slot 61.

Each arm clamp comprises a pair of parallel arms 72 and 73 interconnected at their rearward end by connecting rod 74 which is centrally connected to the arm 66. The forward end of the arms 72 and '73 of the arm clamps 47, 4S, 49 and 51 have attached respectively thereto wrapping rods 76, 77, 78 and 79 which are utilized to wrap the respective flanges 17, 17a, 13 and 16a around the respective seat frame bars 24, 26, 27 and 23. The wrapping rods extend substantially the length of their respective anges and are contoured to the curvature of their respective anges.

In operation, the anges 17, 17a, 1S and 18a are heated as described above, until they lare sufficiently pliable. The guide sleeves S3 and 5S are in a predetermined relationship to one another such that when the heating casings 37 and 38 are removed and the vertical guide sleeve 53 is raised, the pivot arms 66 and corresponding arm clamps are simultaneously moved vertically upwardly towards the table top. The pivot arms are rst guided by the guide arm vertical slot portions 62 and then, as the guide rolls 71 encounter the slanted slot portions 64, the arm clamps are moved both horizontally and vertically until the wrapping rods 76, 77, 78 and 79 are moved adjacent their respective seat flanges with the rollers 71 being approximately intermediate the slot portions 64, as is illustrated by FIGURE 4, with the wrapping rods slightly above their respective seat trarne bars. Then, the horizontal control sleeves 53 are simultaneously moved downwardly with the slanting slot portions 61 moving relative to the guide rollers 71 to thereby move the wrapping bars radially inwardly in a straight horizontal plane to bend the anges such that they extend radially inwardly, as is illustrated in FIGURE 5 The length and angle of the slots 64 are predetermined such thatwhen the guide rollers are in the uppermost portion of the slots 64 as is indicated in FIG- URE 5, the Wrapping bars are spaced radially inwardly from their corresponding seat frame bars. Then, the vertical control sleeve 53 is moved downwardly with the guide rollers 71 guided in the vertical guide slot portions 63 to urge the wrapping bars toward the undersurface of the seat until the ends 26 of the flanges meet with the undersurface of the seat face as is shown in FIGURE 6. The wrapping rods may be maintained in this position until the pliable flanges` are cooled by external means (not shown) such that they are once again in their hard state.

The arm clamps are reinstated to their original positionsl by reversing the motion of the vertical control sleeve and the horizontal control sleeves. That is, the vertical control sleeve is raised to its position illustrated in FIG- URE 5, then the horizontal control sleeves are raised simultaneously to their position illustrated in FIGURE 4, and then the vertical control sleeve is lowered to its position illustrated in FIGURE 3.

The flanges are heated only until the plastic is Sulliciently pliable and not so that the plastic is adhesively soft and running. In other words, the flanges preferably do not adhere to Iany portion of the seat underside or of the seat frame bars.

It is of course understood, that it desired, the wrapping rods may be placed in the position illustrated in FIG- URE 3 before the anges are cooled in their wrapped position to form the chair S1 as illustrated in FIGURE 7.

The chair 81 is a rod iron chair having the wrapped thermoplastic seat 16 with four rod iron legs 29, a rod -iron back rest S2, and a pair of rod iron arm rests 83.

Therefore, it is seen where we have provided an improved method for making chairs with thermoplastic seats which are wrapped around the chair seats frame by first providing a thermoplastic seat with four separate outwardly extending tlange or lip members, heating said tlange members until said plastic becomes pliable, then wrapping Vsaid pliable flange members around the chair seat -frarne to attach said seat seat to said frame with the ends of the wrap-around anges abutting the underside of the seat and with the sides of adjacent wrapped llanges being separated, and cooling said wrapped around flanges.

it is of course understood that our above embodiment is only for exemplary purposes and that a great number of other modilications and embodiments will become readily apparent to those skilled in the art. Therefore, our invention is not to be limited to the particular arrangement and method shown and described but should encompass all modilications within the spirit and scope of the hereunto appended claims.

I claim as our invention:

l. A method of manufacturing a chair having a metal seat frame, legs connected to said seat frame, and a hard thermoplastic seat unbiasediy wrapped around said seat frame comprising:

placing a hard thermoplastic seat, having hard integral flanges extending therefrom, onto the seat frame with the seat frame being in engagement with the underside or" the seat and spaced radially inwardly from the anges,

simultaneously heating the ilanges to a predetermined pliability wherein the plastic is pliable and maintained in its solid non-adhering non-owing state, simultaneously bending the pliable llanges around the seat frame until the ends of the flanges contact the underside of the seat,

maintaining the pliable ilanges in nonaadhering unbiased relationship with the seat frame and the underside of the seat,

maintaining the flange ends in contact with the underside of the seat, and

cooling said pliable ilanges to harden said pliable flanges with their ends in contact with the underside of the seat whereby the thermoplastic seat is wrapped around the seat frame to secure the seat thereto in an unbiased condition.

2. A method of manufacturing a chair having :a metal seat frame, and a hard one-piece thermoplastic seat having separate danges unbiasedly wrapped :around said seat frame comprising:

placing a hard thermoplastic seat, having a plurality of separate integral ilanges extending downwardly for a predetermined distance from the seat, onto the seat frame with the seat frame being in engagement with the underside of the seat and the inner surfaces of the anges,

simultaneously heating the flanges to la predetermined pliability wherein the plastic is pliable and still maintained in its solid non-iiowing state,

simultaneously bending the pliable flanges around the seat frame until the ends of the anges contact the underside of the seat,

maintaining the anges in unbiased relationship with the seat frame,

cooling said pliable ilanges to harden said pliable anges with their ends in contact with the underside of the seat, whereby the thermoplastic seat is wrapped around the seat frame to secure the seat thereto in an unbiased condition.

ing `downwardly from said seat frame, a rod iron back rest extending upwardly from the rear seat frame bar,

la pair of rod iron arm rests linterconnecting the back rest with two side seat frame bars, `and a hard thermoplastic seat having four separate llanges unbiased-ly wrapped around said seat frame comprising:

placing a thermoplastic seat, having a concave top 'face and four separate 'integral llanges extending downwardly for a predetermined distance from the seat face, onto 'the seat frame with flanges extending a predetermined distance beyond the seat frame bars and ythe seat frame bars being in VVengagement with the underside of the seat and the inner surfaces of the llanges,

Vsimultaneously heating the four flanges to a predetermined pliability 4wherein the plastic is pliable and maintained in its solid non-adhering non-flowing state,

simultaneously bendingthe pliable flanges radially inwardly over the seat-trarne bars,

simultaneously bending the pliable llanges around the seat frame until the ends of the anges contact the underside of the seat,

maintaining the flanges in non-adhering relationship with the seat trame and the underside of the seat .and in an unbiased condition,

maintaining the ilange ends in contact with the underside of the seat,

cooling said pliable flanges to harden said pliable flanges with their ends in contact with the underside of the seat,

whereby the thermoplastic seat is wrapped around the seat trame to secure the seat thereto in an unbiased condition.

4. A method of attaching a hard thermoplastic seat to a rod iron chair having a metal seat frame comprising:

placing the hard thermoplastic seat onto the seat frame with the seat frame,

simultaneously heating predetermined portions of the seat to a predetermined pliability wherein the plastic is pliable and still maintained in its solid non-adhering state,

simultaneously bending the pliable seat portions around the seat `frame,

maintaining the seat portions in non-adhering and unbiased relationship with the seat frame,

cooling said pliable seat portion to harden said pliable seat portions,

whereby the thermoplastic seat is wrapped around the seat frame to secure the seat thereto in an unbiased condition.

5. A method of attaching a hard thermoplastic seat having a plurality of separate integral llanges extending from the seat, to a rectangular metal seat frame, and a hard thermoplastic having -four separate flanges unbiasedly wrapped around said seat frame comprising:

placing the hard thermoplastic seat onto the seat trame with the seat frame being in unbiased engagement with the underside of the seat face and the inner surfaces of the flanges,

simultaneously heating the flanges to a predetermined pli'ability wherein the plastic is pliable and still maintained in its solid non-adhering state,

simultaneously bending the pliable flanges around the seat frame until the ends of the lianges contact the underside of the seat,

maintaining the anges in non-adhering and unbiasing relationship with the seat frame, and

cooling said flanges to harden said pliable ilanges with their ends in contact with the underside of the seat,

whereby the thermoplastic seat is Wrapped around the seat frame to secure the seat thereto in an unbiased condition.

6. A method of attaching a hard thermoplastic seat having a concave top face and four separate integral flanges extending downwardly for a predeterminedv distance from the seat to a rod iron chair having a rectangular rod iron seat lframe having two side bars interconnected at their one end by a front bar and at their other end by a rear bar, comprising:

placing the thermoplastic seat onto the seat frame with ilanges extending a predetermined distance beyond the seat frame bars and the seat frame bars being in engagement with the underside of the seat and the inner surfaces of the anges, simultaneously heating the four anges to a predetermined pliability wherein the plastic is pliable and maintained in its solid non-adhering state,

simultaneously bending the pliable anges around the seat frame until the ends of the ilanges contact the underside of the seat,

maintaining the anges in non-adhering relationship with the seat frame and the underside of the seat and in an unbiased condition,

maintaining the ange ends in contact with the underside of the seat, cooling said pliable anges t0 harden said pliable flanges with their ends in contact with the underside of the.

seat,

whereby the thermoplastic seat is wrapped around the seat frame to secure the seat thereto in an unbiased con- 20 WHITMORE A. WILTZ, Primary Examiner.

FRANK B. SHERRY, Examiner.

THOMAS H. EAGER, CASMIR A. NUNBERG,

Assistant Examiners. 

1. A METHOD OF MANUFACTURING A CHAIR HAVING A METAL SEAT FRAME, LEGS CONNECTED TO SAID SEAT FRAME, AND A HARD THERMOPLASTIC SEAT UNBIASEDLY WRAPPED AROUND SAID SEAT FRAME COMPRISING: PLACING A HARD THERMOPLASTIC SEAT, HAVING HARD INTEGRAL FLANGES EXTENDING THEREFROM, ONTO THE SEAT FRAME WITH THE SEAT FRAME BEING IN ENGAGEMENT WITH THE UNDERSIDE OF THE SEAT AND SPACED RADIALLY INWARDLY FROM THE FLANGES, SIMULTANEOUSLY HEATING THE FLANGES TO A PREDETERMINED PLIABILITY WHEREIN THE PLASTIC IS PLIABLE AND MAINTAINED IN ITS SOLID NON-ADHERING NON-FLOWING STATE, SIMULTANEOUSLY BENDING THE PLIABLE FLANGES AROUND THE SEAT 